Many factors including environmental responsibility and modern environmental regulations on engine exhaust emissions have reduced allowable acceptable levels of certain pollutants that may enter the atmosphere following the combustion of fossil fuels. Increasingly more stringent emission standards require greater control over both the combustion of fuel within the engine, and may require post combustion treatment of the exhaust. For example, the allowable levels of nitrogen oxides (NOX) and particulate matter have been greatly reduced over the last several years. To address, among other issues, environmental concerns, many diesel engines now have an exhaust particulate filter within an exhaust system of the engine purposed to reduce the amount of particulate matter released into the atmosphere.
In order to increase the service life of the exhaust particulate filter, an engine may be instructed by an engine control module to perform a regeneration cycle for the exhaust particulate filter that causes exhaust gas temperatures to rise to a level to regenerate the exhaust particulate filter by burning the trapped particulate matter. The regeneration cycle increases the fuel usage of the engine. Thus, it is important to accurately estimate how much particulate matter is within the exhaust gas particulate filter, also referred to as the soot load of the exhaust particulate filter, to prevent premature regeneration of the particulate filter and the increased fuel usage that accompanies the regeneration.